Organic light-emitting display device, method of manufacturing the same, and donor substrate and donor substrate set used to manufacture the organic light-emitting display device

ABSTRACT

An organic light-emitting display device, a method of manufacturing the same, and a donor substrate and a donor substrate set used to manufacture the organic light-emitting display device. According to an aspect of the present invention, there is provided an organic light-emitting display device comprising a substrate which comprises a green region and a red region, a plurality of first electrodes which are formed on the green region and the red region of the substrate, respectively, a plurality of light-emitting layers which are formed on the first electrodes and comprise a green light-emitting layer formed on the green region and a red light-emitting layer formed on the red region, and a second electrode which is formed on the light-emitting layers, wherein the green light-emitting layer comprises a first light-emitting layer which comprises a first host material and a first dopant material and a first buffer layer which is formed on the first light-emitting layer and comprises the first host material, and the red light-emitting layer comprises a second light-emitting layer which comprises a second host material and a second dopant material and a second buffer layer which is formed on the second light-emitting layer and comprises the first host material.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.13/966,277, filed Aug. 13, 2013, which claims priority to and thebenefit of Korean Patent Application No. 10-2013-0032291, filed Mar. 26,2013, the entire content of both of which is incorporated herein byreference.

BACKGROUND

1. Field

The present invention relates to an organic light-emitting displaydevice, a method of manufacturing the same, and a donor substrate and adonor substrate set used to manufacture the organic light-emittingdisplay device.

2. Description of the Related Art

Generally, an organic light-emitting display device includes an anode, acathode, and organic layers interposed between the anode and thecathode. The organic layers include at least a light-emitting layer andmay further include a hole injection layer, a hole transport layer, anelectron transport layer and an electron injection layer, in addition tothe light-emitting layer. The organic light-emitting display device isclassified as a polymer organic light-emitting display device or a smallmolecule organic light-emitting display device depending on the materialthat forms the organic layer, particularly, the light-emitting layer.

In order to realize a full-color organic light-emitting display device,it is required to pattern the light-emitting layer. The light-emittinglayer may be patterned using a fine metal mask (FMM) in the case of thesmall molecule organic light-emitting display device and using inkjetprinting or laser induced thermal imaging (LITI) in the case of thepolymer organic light-emitting display device. Among others, the LITImethod has the advantages of finely patterning the organic layer as wellas being a dry process instead of a wet process as in the inkjetprinting method.

In order to form the pattern of the polymer organic layer using the LITImethod, at least a light source, a substrate for an organiclight-emitting display device, i.e., a device substrate, and a donorsubstrate are required. The donor substrate includes a base film, alight-to-heat conversion layer, and a transfer layer composed of anorganic layer. The patterning of the organic layer on the devicesubstrate is performed while light emitted from the light source isabsorbed into the light-to-heat conversion layer and converted into heatenergy. The organic layer composing the transfer layer is transferredonto the device substrate by the heat energy.

Different base films may be used for a donor substrate for forming agreen light-emitting layer and a donor substrate for forming a redlight-emitting layer. In addition, a buffer layer inserted between thebase film of the donor substrate for forming the green light-emittinglayer and a transfer layer for forming the green light-emitting layermay be different from a buffer layer inserted between the base film ofthe donor substrate for forming the red light-emitting layer and atransfer layer for forming the red light-emitting layer. If differentbase films and buffer layers are used, the number of process variablesmay increase, and it may be difficult to identify the cause of defects.Furthermore, an organic light-emitting display device manufactured usingthe LITI method with different base films and buffer layers may have lowluminous efficiency and a short lifetime.

SUMMARY

Aspects of the present invention provide an organic light-emittingdisplay device which has high luminous efficiency and a long lifetime.

Aspects of the present invention also provide a donor substrate setwhich uses the same base film and the same buffer layer.

Aspects of the present invention also provide a single donor substratewhich uses a common base film and a common buffer layer.

Aspects of the present invention also provide a method of manufacturingan organic light-emitting display device using a donor substrate setwhich uses the same base film and the same buffer layer or a singledonor substrate which uses a common base film and a common buffer layer.

However, aspects of the present invention are not restricted to the oneset forth herein. The above and other aspects of the present inventionwill become more apparent to one of ordinary skill in the art to whichthe present invention pertains by referencing the detailed descriptionof the present invention given below.

According to an embodiment of the present invention, there is provided aorganic light-emitting display device including: a substrate including agreen region and a red region; a plurality of first electrodes, theplurality of first electrodes including a plurality of green regionfirst electrodes and a plurality of red region first electrodes; theplurality of green region first electrodes being on the green region ofthe substrate, and the plurality of red region first electrodes being onthe red region of the substrate; a plurality of light-emitting layers onthe first electrodes, the plurality of light-emitting layers including agreen light-emitting layer on the green region and a red light-emittinglayer on the red region; and a second electrode on the light-emittinglayers, the green light-emitting layer including a first light-emittinglayer including: a first host material; and a first dopant material; anda first buffer layer on the first light-emitting layer, including thefirst host material, and the red light-emitting layer including: asecond light-emitting layer including: a second host material; and asecond dopant material, and a second buffer layer on the secondlight-emitting layer including the first host material.

In one embodiment, the substrate further includes a blue region, and thelight-emitting layers further include a blue light-emitting layer on theblue region.

In one embodiment, the blue light-emitting layer extends into the greenregion and the red region and overlaps with the green light-emittinglayer and the red light-emitting layer.

In one embodiment, the green light-emitting layer and the redlight-emitting layer are directly on the blue light-emitting layer.

In one embodiment, the blue light-emitting layer includes a third hostmaterial and a third dopant material.

In one embodiment, the display includes: a first medium layer configuredto inject or transport electrons or holes between the first electrodesand the blue light-emitting layer; and a second medium layer configuredto inject or transport electrons or holes between the light-emittinglayers and the second electrode.

In one embodiment, the first buffer layer does not include the firstdopant material; and the second buffer layer does not include the seconddopant material.

In one embodiment, the green light-emitting layer includes a firstauxiliary layer under the first light-emitting layer, and the redlight-emitting layer includes a second auxiliary layer under the secondlight-emitting layer.

In one embodiment, a height of the second auxiliary layer is greaterthan a height of the first auxiliary layer.

In one embodiment, the display includes a passivation layer formed onthe second electrode configured to protect the second electrode andstructures under the second electrode.

According to an embodiment of the present invention, there is provided adonor substrate set including: a first donor substrate; and a seconddonor substrate, the first donor substrate including: a first base film;a transfer layer for forming a first buffer layer, the transfer layerfor forming the first buffer layer being on the first base film andincluding a first host material; and a transfer layer for forming afirst light-emitting layer, the transfer layer for forming the firstlight-emitting layer being on the transfer layer for forming the firstbuffer layer, the transfer layer for forming the first light-emittinglayer including the first host material and a first dopant material, andthe second donor substrate including: a second base film, a transferlayer for forming a second buffer layer, the transfer layer for formingthe second buffer layer being on the second base film and including thefirst host material; and a transfer layer for forming a secondlight-emitting layer, the transfer layer for forming the secondlight-emitting layer being on the transfer layer for forming the secondbuffer layer and including a second host material and a second dopantmaterial.

In one embodiment, the first base film and the second base film arecomposed of the same material.

In one embodiment, the transfer layer for forming the first buffer layerand the transfer layer for forming the second buffer layer are composedof the same material.

In one embodiment, the transfer layer for forming the first buffer layerdoes not include the first dopant material; and the transfer layer forforming the second buffer layer does not include the second dopantmaterial.

In one embodiment, the donor includes: a transfer layer for forming afirst auxiliary layer, the transfer layer for forming the firstauxiliary layer being on the transfer layer for forming the firstlight-emitting layer; and a transfer layer for forming a secondauxiliary layer, the transfer layer for forming the second auxiliarylayer being on the transfer layer for forming the second light-emittinglayer.

In one embodiment, the donor includes: a first light-to-heat conversionlayer between the first base film and the transfer layer for forming thefirst buffer layer; and a second light-to-heat conversion layer betweenthe second base film and the transfer layer for forming the secondbuffer layer.

In one embodiment, the donor includes: a first intermediate layerbetween the first light-to-heat conversion layer and the transfer layerfor forming the first buffer layer; and a second intermediate layerbetween the second light-to-heat conversion layer and the transfer layerfor forming the second buffer layer.

According to an embodiment of the present invention, there is provided adonor substrate including: a base film including a first region and asecond region; a buffer layer on the base film, the buffer layerincluding a first host material; a transfer layer for forming a firstlight-emitting layer, the transfer layer for forming the firstlight-emitting layer being on the first region of the buffer layer andincluding the first host material and a first dopant material; and atransfer layer for forming a second light-emitting layer, the transferlayer for forming the second light-emitting layer being on the secondregion of the buffer layer and including a second host material and asecond dopant material.

In one embodiment, the donor includes: a transfer layer for forming afirst auxiliary layer, the transfer layer for forming the firstauxiliary layer being on the transfer layer for forming the firstlight-emitting layer; and a transfer layer for forming a secondauxiliary layer, the transfer layer for forming the second auxiliarylayer being on the transfer layer for forming the second light-emittinglayer.

In one embodiment, the donor includes a light-to-heat conversion layerwhich is formed between the base film and the buffer layer.

In one embodiment, the donor includes an intermediate layer between thelight-to-heat conversion layer and the buffer layer.

According to an embodiment of the present invention, there is provided amethod of manufacturing an organic light-emitting display device, themethod including: preparing a substrate having a plurality of firstelectrodes respectively formed on a first region and a second region ofthe substrate; placing a first donor substrate including a first basefilm, a transfer layer for forming a first buffer layer, the transferlayer for forming the first buffer layer being on the first base filmand including a first host material, and a transfer layer for forming afirst light-emitting layer, the transfer layer for forming the firstlight-emitting layer being on the transfer layer for forming the firstbuffer layer and including the first host material and a first dopantmaterial, such that the transfer layer for forming the firstlight-emitting layer faces the substrate with a gap between the transferlayer for forming the first light-emitting layer and the substrate; andforming a first organic layer pattern on the first electrode of thefirst region by transferring the transfer layer for forming the firstbuffer layer and the transfer layer for forming the first light-emittinglayer onto the first electrode of the first region by irradiating thefirst region with a laser beam.

In one embodiment, the method includes, after the forming of the firstorganic layer pattern on the first electrode of the first region:placing a second donor substrate including a second base film, atransfer layer for forming a second buffer layer, the transfer layer forforming the second buffer layer being on the second base film andincluding the first host material, and a transfer layer for forming asecond light-emitting layer, the transfer layer for forming the secondlight-emitting layer being formed on the transfer layer for forming thesecond buffer layer and including a second host material and a seconddopant material, such that the transfer layer for forming the secondlight-emitting layer faces the substrate with a gap between the transferlayer for forming the second light-emitting layer and the substrate; andforming a second organic layer pattern on the first electrode of thesecond region by transferring the transfer layer for forming the secondbuffer layer and the transfer layer for forming the secondlight-emitting layer onto the first electrode of the second region byirradiating the second region with a laser beam.

In one embodiment, the method includes, after the forming of the secondorganic layer pattern on the first electrode of the second region,forming a second electrode on the first organic layer pattern and thesecond organic layer pattern.

According to an embodiment of the present invention there is provided amethod of manufacturing an organic light-emitting display device, themethod including: preparing a substrate having a plurality of firstelectrodes formed on a first region and a second region of thesubstrate; placing a donor substrate including a base film, a bufferlayer on the base film and including a first host material, a transferlayer for forming a first light-emitting layer, the transfer layer forforming the first light-emitting layer being on the buffer layer of thefirst region and including the first host material and a first dopantmaterial, and a transfer layer for forming a second light-emittinglayer, the transfer layer for forming the second light-emitting layerbeing on the buffer layer of the second region and including a secondhost material and a second dopant material, such that the transfer layerfor forming the first light-emitting layer and the transfer layer forforming the second light-emitting layer face the substrate with a gapbetween: the transfer layer for forming the first light-emitting layerand the transfer layer for forming the second light-emitting layer; andthe substrate; and forming organic layer patterns on the firstelectrodes by transferring the buffer layer, the transfer layer forforming the first light-emitting layer and the transfer layer forforming the second light-emitting layer onto the first electrodes byirradiating the first region and the second region with a laser beam.

In one embodiment, the method includes, after the forming of the organiclayer patterns on the first electrodes, forming a second electrode onthe organic layer patterns.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the present invention willbecome more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings, in which:

FIG. 1 is a cross-sectional view of an organic light-emitting displaydevice according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a donor substrate set according toan embodiment of the present invention;

FIGS. 3 and 4 are cross-sectional views respectively illustrating stepsof a method of manufacturing an organic light-emitting display deviceusing the donor substrate set of FIG. 2;

FIG. 5 is a cross-sectional view of a donor substrate according to anembodiment of the present invention;

FIGS. 6 and 7 are cross-sectional views respectively illustrating stepsof a method of manufacturing an organic light-emitting display deviceusing the donor substrate of FIG. 5; and

FIG. 8 is a graph illustrating luminance reduction rates over time oforganic light-emitting display devices manufactured according toExamples 1 and 2 and Comparative Examples 1 and 2.

DETAILED DESCRIPTION

Aspects and features of the present invention and methods ofaccomplishing the same may be understood more readily by reference tothe following detailed description of embodiments and the accompanyingdrawings. The present invention may, however, be embodied in manydifferent forms and should not be construed as being limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete and will fully conveythe concept of the invention to those skilled in the art, and thepresent invention will only be defined by the appended claims. Thus, insome embodiments, well-known structures and devices are not shown inorder not to obscure the description of the invention with unnecessarydetail. Like numbers refer to like elements throughout. In the drawings,the thickness of layers and regions are exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on,” or “connected to” another element or layer, it can bedirectly on or connected to the other element or layer or interveningelements or layers may be present. In contrast, when an element isreferred to as being “directly on” or “directly connected to” anotherelement or layer, there are no intervening elements or layers present.As used herein, the term “and/or” includes any and all combinations ofone or more of the associated listed items.

Spatially relative terms, such as “below,” “beneath,” “lower,” “above,”“upper,” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures.

Embodiments described herein will be described referring to plan viewsand/or cross-sectional views by way of ideal schematic views of theinvention. Accordingly, the exemplary views may be modified depending onmanufacturing technologies and/or tolerances. Therefore, the embodimentsof the invention are not limited to those shown in the views, butinclude modifications in configuration formed on the basis ofmanufacturing processes. Therefore, regions exemplified in figures areschematic representations and shapes of regions shown in figuresexemplify specific shapes of regions of elements and do not limitaspects of the invention.

Hereinafter, embodiments of the present invention will be described withreference to the attached drawings.

FIG. 1 is a cross-sectional view of an organic light-emitting displaydevice according to an embodiment of the present invention. Referring toFIG. 1, the organic light-emitting display device includes a substrate100, a plurality of first electrodes 110 which are formed on thesubstrate 100, a plurality of light-emitting layers which are formed onthe first electrodes 110 and include a blue light-emitting layer 130, agreen light-emitting layer 140 and a red light-emitting layer 150, and asecond electrode 170 which is formed on the light-emitting layers.

The substrate 100 may include an insulating substrate. The insulatingsubstrate may be formed of a transparent glass material containingtransparent SiO₂ as its main component. In some embodiments, theinsulating substrate may be formed of an opaque material or a plasticmaterial. Further, the insulating substrate may be a flexible substratethat can be bent, folded or rolled.

Although not shown in FIG. 1, the substrate 100 may further includeother structures formed on the insulating substrate. Examples of thestructures may include wiring lines, electrodes, insulating layers, etc.If the organic light-emitting display device according to the currentembodiment is an active matrix organic light-emitting display device,the substrate 100 may include a plurality of thin-film transistors(TFTs) formed on the insulating substrate. Each of the TFTs may includea gate electrode, a source electrode, a drain electrode and asemiconductor layer which is a channel region. The semiconductor layermay be formed of amorphous silicon, polycrystalline silicon, ormonocrystalline silicon. In an alternative embodiment, the semiconductorlayer may be formed of an oxide semiconductor. The drain electrode ofeach of at least some of the TFTs may be electrically connected to acorresponding one of the first electrodes 110.

The substrate 100 may include a blue region, a green region and a redregion. The blue region, the green region and the red region may emitlight of blue, green and red colors, respectively. In an exemplaryembodiment, the blue region, the green region and the red region of thesubstrate 100 may be separated from each other by a predetermineddistance.

The first electrodes 110 are formed on the substrate 100. The firstelectrodes 110 may be separated from each other and may correspond to aplurality of pixels, respectively. Although not shown in FIG. 1, a pixeldefining layer may be interposed between the first electrodes 110 ofdifferent pixels to define the pixels. The pixel defining layer may beformed on the substrate 100 and may include openings which exposeregions in which the first electrodes 110 of the pixels are to beformed, respectively. The pixel defining layer may be formed of at leastone organic material selected from benzocyclobutene (BCB), polyimide(PI), polyamaide (PA), acrylic resin and phenolic resin or may be formedof an inorganic material such as silicon nitride.

The first electrodes 110 may be anodes or cathodes. If the firstelectrodes 110 are anodes, the second electrode 170 may be a cathode. Acase where the first electrodes 110 are anodes will hereinafter bedescribed as an example. However, this is merely an example, and thefirst electrodes 110 may also be cathodes, and the second electrode 170may also be an anode.

The first electrodes 110 used as anodes may be formed of a conductivematerial with a high work function. In a bottom emission organiclight-emitting display device, the first electrodes 110 may be formed ofITO, IZO, ZnO, In₂O₃, or a stack of these materials. In a top emissionorganic light-emitting display device, each of the first electrodes 110may further include a reflective layer formed of Ag, Mg, Al, Pt, Pd, Au,Ni, Nd, Ir, Cr, Li or Ca. The structure of the first electrodes 110 canbe modified in various forms. For example, the first electrodes 110 mayconsist of two or more layers of two or more different materialsselected from the above materials.

The first electrodes 110 may be formed in the blue region, the greenregion and the red region. The first electrodes 110 may be formed on thesubstrate 100 to directly contact the substrate 100, or a material suchas an insulating layer may be interposed between the first electrodes110 and the substrate 100. The phrases “green region” and “red region”may be used herein to denote these regions respectively, or asattributive adjective phrases, to identify, for example, the firstelectrodes in these regions. Thus, for example, a first electrode in thegreen region may be referred to herein as a “green region firstelectrode.”

A first medium layer 120 may be formed on the first electrodes 110. Thefirst medium layer 120 may help the injection or transportation ofelectrons or holes between the first electrodes 110 and the secondelectrode 170. If the first electrodes 110 are anodes, the first mediumlayer 120 may be a layer related to the injection or transportation ofholes. For example, the first medium layer 120 may include a holeinjection layer or a hole transport layer only or may include a stack ofthe hole injection and the hole transport layer. The hole injectionlayer or the hole transport layer may be formed using various methodsincluding vapor deposition, spin coating, casting, and LB methods. Thevapor deposition method may be used.

When the hole injection or the hole transport layer is formed by thevapor deposition method, its deposition conditions may vary according toa compound used as the material that forms the hole injection layer orthe hole transport layer and the intended structure and thermalcharacteristics of the hole injection layer or the hole transport layer.The deposition conditions of the hole injection layer or the holetransport layer may include a deposition temperature ranging from 100 to500° C., a vacuum level ranging from 10⁻⁸ to 10 ⁻³ torr, and adeposition rate ranging from 0.01 to 100 Å/sec.

The material that forms the hole injection layer may be selected fromknown hole injection materials including, but not limited to, aphthalocyanine compound such as copper phthalocyanine, a starburst typeamine derivative such as TCTA or m-MTDATA, a conductive polymer such aspolyaniline/dodecylbenzenesulfonic acid (Pani/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (Pani/CSA), and polyaniline/poly(4-styrene-sulfonate)(PAN I/PSS).

The material that forms the hole transport layer may be selected fromknown hole transport materials including, but not limited to,1,3,5-tricarbazolyl benzene, 4,4′-biscarbazolylbiphenyl,polyvinylcarbazole, m-biscarbazolylphenyl,4,4′-biscarbazolyl-2,2′-dimethylbiphenyl,4,4′,4″-tri(N-carbazolyl)triphenylamine,1,3,5-tri(2-carbazolylphenyl)benzene,1,3,5-tris(2-carbazolyl-5-methoxyphenyl)benzene,bis(4-carbazolylphenyl)-silane,N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine(TPD),N,N′-di(naphthalene-1-yl)-N,N′-diphenyl benzidine (NPD),N,N′-diphenyl-N,N′-bis(1-naphthyl)-(1,1′-biphenyl)-4,4′-diamine (NPB),poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine) (TFB), andpoly(9,9-dioctylfluorene-co-bis-(4-butylphenyl)-bis-N,N-phenyl-1,4-phenylenediamine)(PFB).

The first medium layer 120 may be divided into a plurality of sectionscorresponding respectively to the pixels. Alternatively, the firstmedium layer 120 may be formed as a single piece over the entire organiclight-emitting display device, as shown in FIG. 1. That is, the firstmedium layer 120 may be formed as a common layer regardless of thedivision between the pixels.

The blue light-emitting layer 130 is formed on the first medium layer120. The blue light-emitting layer 130 may be formed in the blue region.The blue light-emitting layer 130 may be formed of a polymer material ora small molecule organic material which uniquely emits blue light or amixture of the polymer material and the small molecule organic material.In some embodiments, the blue light-emitting layer 130 may include ablue host material and a blue dopant material.

The blue host material of the blue light-emitting layer 130 may includeone or more materials selected from, but not limited to, an anthracenederivative and a carbazole compound. The anthracene derivative may be9,10-(2-dinaphthyl) anthracene (ADN), and the carbazole compound may be4,4′-(carbazole-9-yl)biphenyl (CBP).

The blue dopant material of the blue light-emitting layer 130 may be,but is not limited to being, F₂lrpic, (F₂ppy)₂Ir(tmd), It(dfppz)₃,ter-fluorene, etc.

The blue light-emitting layer 130, like the first medium layer 120, maybe formed as a common layer regardless of the division between thepixels. That is, the blue light-emitting layer 130 may be formed notonly in the blue region but may also extend to the green region and thered region to be overlapped by the green light-emitting layer 140 andthe red light-emitting layer 150. In an exemplary embodiment, the greenlight-emitting layer 140 and the red light-emitting layer 150 may beformed directly on the blue light-emitting layer 130.

In the green region, the green light-emitting layer 140 may be formed onthe blue light-emitting layer 130. In the red region, the redlight-emitting layer 150 may be formed on the blue light-emitting layer130. The green light-emitting layer 140 and the red light-emitting layer150 may be formed by, but not limited to, a laser induced thermalimaging (LITI) method. A second medium layer 160 may be formed on thegreen light-emitting layer 140 and the red light-emitting layer 150. Inthe green region and the red region, the blue light-emitting layer 130,like the first medium layer 120, may transport carriers, and its lightemission may be limited. On the other hand, in the blue region, thesecond medium layer 160 may be formed on the blue light-emitting layer130 with no light-emitting layer interposed therebetween. In the blueregion, the blue light-emitting layer 130 may emit light of its uniquecolor, i.e., blue light. The second medium layer 160 will be describedin more detail later.

The green light-emitting layer 140 may include a first auxiliary layer141, a first light-emitting layer 142, and a first buffer layer 143stacked sequentially.

The first auxiliary layer 141 may adjust a thickness of the greenlight-emitting layer 140 in order to control the resonance cycle ofgreen light. In order to increase the luminous efficiency, color purity,etc. of green light, a thickness of the first auxiliary layer 141 may beset in a range of 300 to 1500 Å. The first auxiliary layer 141 may beformed only in the green region by using a fine metal mask (FMM). Thematerial that forms the first auxiliary layer 141 may be, but is notlimited to being, identical to the material that forms the holetransport layer. In an exemplary embodiment, the first auxiliary layer141 may include at least one material selected from silicon nitride(SiNx), silicon oxide (SiO₂), and silicon oxynitride (SiON).

The first light-emitting layer 142 may be formed of a polymer materialor a small molecule organic material which uniquely emits green light ora mixture of the polymer material and the small molecule organicmaterial. In some embodiments, the first light-emitting layer 142 mayinclude a green host material and a green dopant material.

The green host material (a first host material) of the firstlight-emitting layer 142 may include one or more materials selectedfrom, but not limited to, an anthracene derivative and a carbazolecompound. The anthracene derivative may be ADN, and the carbazolecompound may be CBP.

The green dopant material (a first dopant material) of the firstlight-emitting layer 142 may be, but is not limited to, Ir(ppy)₃(ppy=phenylpyridine), Ir(ppy)₂(acac), Ir(mpyp)₃, or C545T,

The first buffer layer 143 may include the first host material. That is,the first buffer layer 143 may not include the first dopant material. Inan exemplary embodiment, the first buffer layer 143 may be formed of thefirst host material only.

The red light-emitting layer 150 may include a second auxiliary layer151, a second light-emitting layer 152, and a second buffer layer 153stacked sequentially.

The second auxiliary layer 151 may adjust a thickness of the redlight-emitting layer 150 in order to control the resonance cycle of redlight. In order to increase the luminous efficiency, color purity, etc.of red light, a thickness of the second auxiliary layer 151 may be setin a range of 500 to 1800 Å. In an exemplary embodiment, a height of thesecond auxiliary layer 151 may be greater than a height of the firstauxiliary layer 141. The second auxiliary layer 151 may be formed onlyin the red region by using an FMM. The material that forms the secondauxiliary layer 151 may be, but is not limited to being, identical tothe material that forms the hole transport layer. In an exemplaryembodiment, the second auxiliary layer 151 may include at least onematerial selected from SiNx, SiO₂, and SiON.

The second light-emitting layer 152 may be formed of a polymer materialor a small molecule organic material which uniquely emits red light or amixture of the polymer material and the small molecule organic material.In some embodiments, the second light-emitting layer 152 may include ared host material and a red dopant material.

The red host material (a second host material) of the secondlight-emitting layer 152 may include, but not be limited to, one or morematerials selected from the group consisting ofbis(2-(2-hydroxyphenyl)benzothiazolato)zinc (Zn(BTZ)2) andbis-(2-methyl-8-quinolinolate)-4-(phenylphenolate)aluminum.

The red dopant material (a second dopant material) of the secondlight-emitting layer 152 may be, but is not limited to being, PtOEP,Ir(piq)₃,Btp₂Ir(acac), DCJTB, etc.

The second buffer layer 153 may include the first host material. Thatis, the second buffer layer 153 may not include the second dopantmaterial. In an exemplary embodiment, the second buffer layer 153 may beformed of the first host material only. In another exemplary embodiment,the second buffer layer 153 may be formed of the same material as thefirst buffer layer 143.

The second medium layer 160 may be formed on the light-emitting layersnot covered with the pixel defining layer. The second medium layer 160may help the injection or transportation of electrons or holes betweenthe first electrodes 110 and the second electrode 170. If the secondelectrode 170 is a cathode, the second medium layer 160 may be a layerrelated to the injection or transportation of electrons. For example,the second medium layer 160 may include an electron transport layer oran electron injection layer only or may include a stack of the electrontransport layer and the electron injection layer.

The electron transport layer or the electron injection layer may beformed using various methods including vapor deposition and spincoating. When the electron transport layer or the electron injectionlayer is formed using vapor deposition or spin coating, the depositionor coating conditions may vary according to the compound used, but aregenerally almost the same as those for the formation of the holeinjection layer.

The material that forms the electron transport layer may be a materialthat can stably transport electrons injected from a cathode. Thematerial may be, but is not limited to, a quinoline derivative, inparticular, a known material such as tris(8-quinolinorate)aluminum(Alq₃), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butyl phenyl)-1,2,4-triazole(TAZ), Balq, etc.

The electron injection layer may be formed of a known material such as,but not limited to, LiF, NaCI, CsF, Li_(2O), BaO, etc.

The second medium layer 160 may extend onto side and top surfaces of thepixel defining layer. The second medium layer 160 may be divided into aplurality of sections corresponding respectively to the pixels.Alternatively, the second medium layer 160 may be formed as a singlepiece over the entire organic light-emitting display device, as shown inFIG. 1. That is, the second medium layer 160 may be formed as a commonlayer regardless of the division between the pixels. In someembodiments, the second medium layer 160 may be omitted.

The second electrode 170 is formed on the second medium layer 160. Thesecond electrode 170 used as a cathode may be formed of a conductivematerial with a low work function. The second electrode 170 may beformed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li or Ca.

A passivation layer 180 may be disposed on the second electrode 170. Thepassivation layer 170 may be formed of an insulating material. A spacer(not shown) may be disposed between the second electrode 170 and thepassivation layer 180. In some other embodiments of the presentinvention, the passivation layer 180 may be omitted. In this case, anencapsulation layer formed of an insulating material may cover theentire structure to protect the structure.

The organic light-emitting display device according to the currentembodiment can be manufactured using a donor substrate set 200 whichwill be described below. FIG. 2 is a cross-sectional view of a donorsubstrate set 200 according to an embodiment of the present invention.Referring to FIG. 2, the donor substrate set 200 may include a firstdonor substrate 210 and a second donor substrate 220.

The first donor substrate 210 may include a first base film 211, a firstlight-to-heat conversion layer 212, a first intermediate layer 213, anda transfer layer 214 for forming a green light-emitting layer.

The first base film 211 may be formed of transparent polymer, whichincludes polyester such as polyethylene terephthalate, polyacryl,polyepoxy, polyethylene, polystyrene, and the like. Among theseexamples, the polyethylene terephthalate film is mainly used. The firstbase film 211 should have optical properties and mechanical stability asa support film. The first base film 211 may have a thickness of 10 to500 μm.

The first light-to-heat conversion layer 212 may be disposed on thefirst base film 211. The first light-to-heat conversion layer 212absorbs light in the infrared-visible range and converts some of thelight into heat. To this end, the first light-to-heat conversion layer212 should have a suitable optical density and includes a lightabsorbing material. The first light-to-heat conversion layer 212 may bea metal layer which contains aluminum oxide or aluminum sulfide as thelight absorbing material or a polymer organic layer which containscarbon black, graphite or infrared dye as the light absorbing material.If the first light-to-heat conversion layer 212 is a metal layer, it maybe formed to a thickness of 100 to 5,000 Å by vacuum deposition,electron beam deposition or sputtering. If the first light-to-heatconversion layer 212 is a polymer organic layer, it may be formed to athickness of 0.1 to 10 μm by typical film coating methods such as rollcoating, gravure coating, extrusion coating, spin coating, and knifecoating.

The first intermediate layer 213 may be formed on the firstlight-to-heat conversion layer 212. The first intermediate layer 212 mayprevent the light absorbing material (e.g., carbon black) of the firstlight-to-heat conversion layer 212 from contaminating the transfer layer214 formed in a subsequent process. The first intermediate layer 213 maybe formed of acrylic resin or alkyd resin. The first intermediate layer213 may be formed by a typical coating process such as solvent coatingand a curing process such as ultraviolet curing.

The transfer layer 214 for forming the green light-emitting layer may bedisposed on the first intermediate layer 213. The transfer layer 214 forforming the green light-emitting layer may include a transfer layer 214a for forming a first buffer layer, a transfer layer 214 b for forming afirst light-emitting layer, and a transfer layer 214 c for forming afirst auxiliary layer stacked sequentially on the first intermediatelayer 213.

The transfer layer 214 a for forming the first buffer layer, thetransfer layer 214 b for forming the first light-emitting layer, and thetransfer layer 214 c for forming the first auxiliary layer may be formedof the same materials as the first buffer layer 143, the firstlight-emitting layer 142, and the first auxiliary layer 141,respectively. The transfer layer 214 a for forming the first bufferlayer, the transfer layer 214 b for forming the first light-emittinglayer, and the transfer layer 214 c for forming the first auxiliarylayer may be formed on the first base film 211 by a typical depositionmethod.

The second donor substrate 220 may include a second base film 221, asecond light-to-heat conversion layer 222, a second intermediate layer223, and a transfer layer 224 for forming a red light-emitting layer.

The second base film 221 may be formed of the same material as the firstbase film 211. In an exemplary embodiment, both the first base film 211and the second base film 221 may be polyethylene terephthalate films. Inaddition, a thickness of the second base film 221 may be equal to thethickness of the first base film 211. In an exemplary embodiment, boththe thickness of the first base film 211 and the thickness of the secondbase film 221 may be 100 μm.

The second light-to-heat conversion layer 222 disposed on the secondbase film 221 may be formed of the same material as the firstlight-to-heat conversion layer 212. In an exemplary embodiment, both thefirst light-to-heat conversion layer 212 and the second light-to-heatconversion layer 222 may be metal layers which contain aluminum oxide asa light-absorbing material. In addition, a thickness of the secondlight-to-heat conversion layer 222 may be equal to the thickness of thefirst light-to-heat conversion layer 212. In an exemplary embodiment,both the thickness of the first light-to-heat conversion layer 212 andthe thickness of the second light-to-heat conversion layer 222 may be1,000 Å.

The second intermediate layer 223 disposed on the second light-to-heatconversion layer 222 may prevent the light absorbing material of thesecond light-to-heat conversion layer 222 from contaminating thetransfer layer 224 formed in a subsequent process. The secondintermediate layer 223 may be formed of the same material as the firstintermediate layer 213. In an exemplary embodiment, both the firstintermediate layer 213 and the second intermediate layer 223 may beformed of acrylic resin.

The transfer layer 224 for forming the red light-emitting layer may bedisposed on the second intermediate layer 223. The transfer layer 224for forming the red light-emitting layer may include a transfer layer224 a for forming a second buffer layer, a transfer layer 224 b forforming a second light-emitting layer, and a transfer layer 224 c forforming a second auxiliary layer stacked sequentially on the secondintermediate layer 223.

The transfer layer 224 a for forming the second buffer layer, thetransfer layer 224 b for forming the second light-emitting layer, andthe transfer layer 224 c for forming the second auxiliary layer may beformed of the same materials as the second buffer layer 153, the secondlight-emitting layer 152, and the second auxiliary layer 151,respectively. The transfer layer 224 a for forming the second bufferlayer, the transfer layer 224 b for forming the second light-emittinglayer, and the transfer layer 224 c for forming the second auxiliarylayer may be formed on the second base film 221 by a typical depositionmethod. Here, the transfer layer 224 a for forming the second bufferlayer may be formed of the same material as the transfer layer 214 a forforming the first buffer layer. That is, both the transfer layer 214 afor forming the first buffer layer and the transfer layer 224 a forforming the second buffer layer may be formed of the green host material(the first host material), e.g., ADN.

A method of manufacturing an organic light-emitting display device usingthe donor substrate set 200 according to an embodiment of the presentinvention will now be described with reference to FIGS. 3 and 4. FIGS. 3and 4 are cross-sectional views respectively illustrating steps of amethod of manufacturing an organic light-emitting display device usingthe donor substrate set 200 of FIG. 2. For simplicity, elementssubstantially identical to those of FIGS. 1 and 2 are indicated by likereference numerals, and thus a repetitive description thereof will beomitted.

Referring to FIGS. 3 and 4, a substrate 100 having a plurality of firstelectrodes 110 respectively formed on a first region (a green region)and a second region (a red region) thereof may be prepared. Then, afirst medium layer 120 and a blue light-emitting layer 130 may bedeposited on the substrate 100 using an open mask. A first donorsubstrate 210 may be formed by a deposition process and then placed suchthat a transfer layer 214 for forming a green light-emitting layerincluding a transfer layer 214 b for forming a first light-emittinglayer faces the substrate 100 with a gap therebetween. The transferlayer 214 for forming the green light-emitting layer may be transferredonto the first electrode 110 of the first region by irradiating thefirst region with a laser beam 400. As a result, a first organic layerpattern, that is, a green light-emitting layer 140 may be formed on thefirst electrode 110 of the first region.

Next, a second donor substrate 220 may be formed by a deposition processand then placed such that a transfer layer 224 for forming a redlight-emitting layer including a transfer layer 224 b for forming asecond light-emitting layer faces the substrate 100 with a gaptherebetween. The transfer layer 224 for forming the red light-emittinglayer may be transferred onto the first electrode 110 of the secondregion by irradiating the second region with the laser beam 400. As aresult, a second organic layer pattern, that is, a red light-emittinglayer 150 may be formed on the first electrode 110 of the second region.

That is, as shown in FIGS. 3 and 4, the first donor substrate 210 andthe second donor substrate 220 can be simultaneously placed on thesubstrate 100, and the transfer layer 214 for forming the greenlight-emitting layer and the transfer layer 224 for forming the redlight-emitting layer can be simultaneously transferred. However, inanother embodiment as described above, after the first donor substrate210 is placed on the substrate 100 and the transfer layer 214 forforming the green light-emitting layer is transferred, the second donorsubstrate 220 may be placed on the substrate 100, and the transfer layer224 for forming the red light-emitting layer may be transferred.

Next, a second medium layer 160, a second electrode 170 and apassivation layer 180 may be stacked sequentially by a depositionprocess.

The organic light-emitting display device according to the embodiment ofFIG. 1 may also be manufactured using a single donor substrate 300. FIG.5 is a cross-sectional view of a donor substrate 300 according to anembodiment of the present invention. Referring to FIG. 5, the donorsubstrate 300 may include a base film 301, a light-to-heat conversionlayer 302, an intermediate layer 303, a buffer layer 304, a transferlayer 305 for forming a first light-emitting layer, a transfer layer 306for forming a first auxiliary layer, a transfer layer 307 for forming asecond light-emitting layer, and a transfer layer 308 for forming asecond auxiliary layer.

The base film 301 may include a first region (a green region) and asecond region (a red region). The base film 301 may be formed of thesame material as the first base film 211 described above.

The light-to-heat conversion layer 302, the intermediate layer 303, andthe buffer layer 304 stacked sequentially on the base film 301 may beformed of the same materials as the first light-to-heat conversion layer212, the first intermediate layer 213, and the first buffer layer 143described above, respectively.

The transfer layer 305 for forming the first light-emitting layer andthe transfer layer 306 for forming the first auxiliary layer may bedeposited sequentially on the buffer layer 304 of the first region by adeposition process.

The transfer layer 307 for forming the second light-emitting layer andthe transfer layer 308 for forming the second auxiliary layer may beformed sequentially on the buffer layer 304 of the second region by adeposition process.

A method of manufacturing an organic light-emitting display device usingthe donor substrate 300 according to another embodiment of the presentinvention will now be described with reference to FIGS. 6 and 7. FIGS. 6and 7 are cross-sectional views respectively illustrating steps of amethod of manufacturing an organic light-emitting display device usingthe donor substrate 300 of FIG. 5. For simplicity, elementssubstantially identical to those of FIGS. 1 through 5 are indicated bylike reference numerals, and thus a repetitive description thereof willbe omitted.

Referring to FIGS. 6 and 7, a substrate 100 having a plurality of firstelectrodes 110 respectively formed on a first region and a second regionthereof may be prepared. Then, a first medium layer 120 and a bluelight-emitting layer 130 may be deposited on the substrate 100 using anopen mask. A donor substrate 300 may be formed by a deposition processand then placed such that a transfer layer 305 for forming a firstlight-emitting layer and a transfer layer 307 for forming a secondlight-emitting layer face the substrate 100 with a gap therebetween. Thefirst region and the second region may be irradiated with a laser beam400, thereby forming organic layer patterns, that is, a greenlight-emitting layer 140 on the first electrode 110 of the first regionand a red light-emitting layer 150 on the first electrode 110 of thesecond region.

Here, a portion of a buffer layer 304 overlapped by the transfer layer305 for forming the first light-emitting layer and a portion of thebuffer layer 304 overlapped by the transfer layer 307 for forming thesecond light-emitting layer may also be transferred, thereby forming afirst buffer layer 143 and a second buffer layer 153, respectively.

Next, a second medium layer 160, a second electrode 170 and apassivation layer 180 may be stacked sequentially by a depositionprocess.

Hereinafter, the present invention will be described in further detailwith reference to the following examples. The following examples are forillustrative purposes only and are not intended to limit the scope ofthe present invention. Luminance reduction rates over time of organiclight-emitting display devices manufactured according to Examples 1 and2 and Comparative Examples 1 and 2 will be described with reference toFIG. 8. FIG. 8 is a graph illustrating luminance reduction rates overtime of organic light-emitting display devices manufactured according toExamples 1 and 2 and Comparative Examples 1 and 2.

EXAMPLE 1

A plurality of first electrodes 110 were formed to a thickness of 500 Åby depositing ITO on a substrate 100, which contains SiO₂ as its maincomponent, using a sputtering method.

A hole injection layer was formed to a thickness of 600 Å by depositingm-MTDATA on the first electrodes 110.

A hole transport layer was formed to a thickness of 150 Å by depositingNPB on the hole injection layer.

A blue light-emitting layer 130, which contains CBP as a blue hostmaterial and F₂Irpic as a blue dopant material, was deposited on thehole injection layer as a common layer by using an open mask. Here, theblue light-emitting layer 130 was formed to a thickness of 400 Å.

A green light-emitting layer 140 was formed on the blue light-emittinglayer 130. The green light-emitting layer 140 was formed by an LITImethod using a first donor substrate 210. The first donor substrate 210was formed by sequentially stacking a first light-to-heat conversionlayer 212 formed of aluminum oxide, a first intermediate layer 213formed of acrylic resin, and a transfer layer 214 for forming a greenlight-emitting layer on a first base film 211 formed of polyethyleneterephthalate. The transfer layer 214 for forming the greenlight-emitting layer was formed by sequentially stacking a transferlayer 214 a for forming a first buffer layer, which was formed of ADN, atransfer layer 214 b for forming a first light-emitting layer, which wasformed of ADN and Ir(ppy)₂(acac), and a transfer layer 214 c for forminga first auxiliary layer, which was formed of NPB, on the firstintermediate layer 213. After the first donor substrate 210 was placedsuch that the transfer layer 214 for forming the green light-emittinglayer faced the substrate 100 with a gap therebetween, the first donorsubstrate 210 and the substrate 100 were irradiated with a laser beam400, thereby forming a green light-emitting layer 140.

In the green light-emitting layer 140, a first auxiliary layer 141, afirst light-emitting layer 142, and a first buffer layer 143 werestacked sequentially. The first auxiliary layer 141 was formed of NPB toa thickness of 300 Å. The first light-emitting layer 142 was formed ofADN (i.e., a green host material) and Ir(ppy)₂(acac) (i.e., a greendopant material) to a thickness of 300 Å. The first buffer layer 143 wasformed of ADN (i.e., the green host material) to a thickness of 300 Å.

An electron transport layer was formed to a thickness of 300 Å bydepositing Alq3 on the green light-emitting layer 140.

An electron injection layer was formed to a thickness of 5 Å bydepositing LiF on the electron transport layer.

A second electrode 170 was formed to a thickness of 800 Å by depositingAl on the electron injection layer.

A passivation layer 180 was formed to a thickness of 500 Å by depositingSiO₂ on the second electrode 170.

An organic light-emitting display device manufactured according toExample 1 showed a maximum current efficiency of 65.2 Cd/A and a maximumpower efficiency of 30.4 Im/W.

In FIG. 8, the luminance reduction rate over time of the organiclight-emitting display device manufactured according to Example 1 isrepresented by a graph A.

EXAMPLE 2

An organic light-emitting display device was manufactured in the sameway as in Example 1 except that a red light-emitting layer 150 wasformed on the above blue light-emitting layer 130. The redlight-emitting layer 150 was formed by an LITI method using a seconddonor substrate 220. The second donor substrate 220 was formed bysequentially stacking a second light-to-heat conversion layer 222 formedof aluminum oxide, a second intermediate layer 223 formed of acrylicresin, and a transfer layer 224 for forming a red light-emitting layeron a second base film 221 formed of polyethylene terephthalate. Thetransfer layer 224 for forming the red light-emitting layer was formedby sequentially stacking a transfer layer 224 a for forming a secondbuffer layer, which was formed of ADN, a transfer layer 224 b forforming a second light-emitting layer, which was formed ofbis-(2-methyl-8-quinolinolate)-4-(phenylphenolate)aluminum and PtOEP,and a transfer layer 224 c for forming a second auxiliary layer, whichwas formed of NPB, on the second intermediate layer 223. After thesecond donor substrate 220 was placed such that the transfer layer 224for forming the red light-emitting layer faced the substrate 100 with agap therebetween, the second donor substrate 220 and the substrate 100were irradiated with the laser beam 400, thereby forming the redlight-emitting layer 150.

In the red light-emitting layer 150, a second auxiliary layer 151, asecond light-emitting layer 152, and a second buffer layer 153 werestacked sequentially. The second auxiliary layer 151 was formed of NPBto a thickness of 500 Å. The second light-emitting layer 152 was formedof bis-(2-methyl-8-quinolinolate)-4-(phenylphenolate)aluminum (i.e., ared host material) and PtOEP (i.e., a red dopant material) to athickness of 300 Å. The second buffer layer 153 was formed of ADN (i.e.,the green host material) to a thickness of 300 Å.

The organic light-emitting display device manufactured according toExample 2 showed a maximum current efficiency of 41.5 Cd/A and a maximumpower efficiency of 18.9 Im/W.

In FIG. 8, the luminance reduction rate over time of the organiclight-emitting display device manufactured according to Example 2 isrepresented by a graph C.

COMPARATIVE EXAMPLE 1

An organic light-emitting display device was manufactured in the sameway as in Example 1 except that a first buffer layer 143 was formed ofbis-(2-methyl-8-quinolinolate)-4-(phenylphenolate)aluminum which is thered host material.

The organic light-emitting display device manufactured according toComparative Example 1 showed a maximum current efficiency of 49.6 Cd/Aand a maximum power efficiency of 23.2 Im/W.

In FIG. 8, the luminance reduction rate over time of the organiclight-emitting display device manufactured according to ComparativeExample 1 is represented by a graph B.

COMPARATIVE EXAMPLE 2

An organic light-emitting display device was manufactured in the sameway as in Example 2 except that a second buffer layer 153 was formed ofbis-(2-methyl-8-quinolinolate)-4-(phenylphenolate)aluminum which is thered host material.

The organic light-emitting display device manufactured according toComparative Example 2 showed a maximum current efficiency of 24.2 Cd/Aand a maximum power efficiency of 9.0 Im/W.

In FIG. 8, the luminance reduction rate over time of the organiclight-emitting display device manufactured according to ComparativeExample 2 is represented by a graph D.

As is apparent from the above examples, a green light-emitting layer(Example 1) including a buffer layer formed of the green host materialexhibited higher luminous efficiency than a green light-emitting layer(Comparative Example 1) including a buffer layer formed of the red hostmaterial. In addition, the green light-emitting layer (Example 1)including the buffer layer formed of the green host material had alonger lifetime than the green light-emitting layer (ComparativeExample 1) including the buffer layer formed of the red host material.Here, the lifetime may correspond to a luminance reduction rate overtime.

Furthermore, a red light-emitting layer (Example 2) including a bufferlayer formed of the green host material exhibited higher luminousefficiency than a red light-emitting layer (Comparative Example 2)including a buffer layer formed of the red host material. In addition,the red light-emitting layer (Example 2) including the buffer layerformed of the green host material had a longer lifetime than the redlight-emitting layer (Comparative Example 2) including the buffer layerformed of the red host material.

When a green light-emitting layer and a red light-emitting layer areformed using an LITI method, the same base film and the same bufferlayer can be used for a donor substrate for forming the greenlight-emitting layer and for a donor substrate for forming the redlight-emitting layer. Therefore, this can reduce the number of processvariables and the time required to identify the cause of defects. Also,material costs can be reduced.

If a buffer layer formed of the green host material is used in the LITImethod, dot non-transfer defects of the green light-emitting layer andthe red light-emitting layer can be improved.

Embodiments of the present invention provide at least one of thefollowing advantages.

That is, since a green light-emitting layer and a red light-emittinglayer include the same buffer layer which contains a green hostmaterial, the luminous efficiency and lifetime of an organiclight-emitting display device can be improved.

In addition, when the green light-emitting layer and the redlight-emitting layer are formed using an LITI method, the same base filmand the same buffer layer can be used for a donor substrate for formingthe green light-emitting layer and for a donor substrate for forming thered light-emitting layer. Therefore, this can reduce process variablesand the time required to identify the cause of defects. Also, materialcosts can be reduced.

If a buffer layer formed of the green host material is used in the LITImethod, dot non-transfer defects of the green light-emitting layer andthe red light-emitting layer can be improved.

However, the effects of the present invention are not restricted to theones set forth herein. The above and other effects of the presentinvention will become more apparent to one of ordinary skill in the artto which the present invention pertains by referencing the claims.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims. It istherefore desired that the present embodiments be considered in allrespects as illustrative and not restrictive, reference being made tothe appended claims rather than the foregoing description to indicatethe scope of the invention.

What is claimed is:
 1. A donor substrate comprising: a base filmcomprising a first region and a second region; a buffer layer on thebase film, the buffer layer comprising a first host material; a transferlayer for forming a first light-emitting layer, the transfer layer forforming the first light-emitting layer being on the first region of thebuffer layer and comprising the first host material and a first dopantmaterial; and a transfer layer for forming a second light-emittinglayer, the transfer layer for forming the second light-emitting layerbeing on the second region of the buffer layer and comprising a secondhost material and a second dopant material.
 2. The donor substrate ofclaim 1, further comprising: a transfer layer for forming a firstauxiliary layer, the transfer layer for forming the first auxiliarylayer being on the transfer layer for forming the first light-emittinglayer; and a transfer layer for forming a second auxiliary layer, thetransfer layer for forming the second auxiliary layer being on thetransfer layer for forming the second light-emitting layer.
 3. The donorsubstrate of claim 1, further comprising a light-to-heat conversionlayer which is formed between the base film and the buffer layer.
 4. Thedonor substrate of claim 3, further comprising an intermediate layerbetween the light-to-heat conversion layer and the buffer layer.